Slow release soil fumigants

ABSTRACT

This invention relates to a slow release soil fumigant that may be utilized in soil without the need of placing a protective cover over soil treated with such fumigant. Broadly, the invention comprises a mixture of a fumigant, a protective colloid and a humectant in water. More particularly, the invention comprises a fumigant consisting essentially of an aqueous solution of about 23 to 36 parts sodium methyl dithiocarbamate, about 60 to 67 parts water, about 1 to 4 parts protective colloid and up to 6 parts humectant.

United States Patent- [191 Wells et al.

SLOW RELEASE SOIL FUMIGANTS Inventors: Wayne W. Wells; James R.Christie; Julian H. Jackson, all of Jacksonville, Fla.

Kerr-McGee Chemical Corp, Oklahoma City, Okla.

Filed: Dec. 15, 1969 Appl. No.: 885,342

Assignee:

References Cited UNITED STATES PATENTS 5/1948 Britton 424/81 1113,820,976 1 June 28, 1974 2,766,554 10/1956 Dorman et a1 47/58 2,791,6055/1957 Dorman et a1 260/5135 2,916,855 12/1959 Thiegs 47/58 PrimaryExaminer-Shep K. Rose Attorney, Agent, or Firm-William G. Addison [S 7]ABSTRACT This invention relates to a slow release soil fumigant that maybe utilized in soil without the need of placing a protective cover oversoil treated with such fumigant. Broadly, the invention comprises amixture of a fumigant, a protective colloid and a humectant in water.More particularly, the invention comprises a fumigant consistingessentially of an aqueous solution of about 23 to 36 parts sodium methyldithiocarbamate, about 60 to 67 parts water, about 1 to 4 partsprotective colloid and up to 6 parts humectanL- 5 Claims, No DrawingsThis invention relates to slow release soil fumigants and particularlyto a film forming soil fumigant which EXAMPLE i A weed killer wasprepared according to the following formula:

1 part of hydroxyethyl cellulose will release its active ingredientslowly and evenly and 5 4 parts of propylene glycol eliminate the needfor a cover over the treated area 95 parts ofa solution of sodium methyldithiocarba during the fumlganon. period mate (37.2 parts of sodiummethyl dithiocarba- The use of soil fumigants to reduce nematodepopumate in 628 parts of water) lation and the population of certainweed forrns is well This formulation was applied to a field along Side aknown f fumlgams are flvallable and standard sodium methyldithiocarbamate fumigant been used the past; however vapor pressuretreatment using a plastic soil cover. The fumigant of Such h has,been necesary to cover P treated this invention was slightly superior in weedelimination area with a plastic covering in order to obtain the most andwas much faster and more convenient to apply effective results. This istime consuming and expensive Since it eliminated the need for a plasticCover since the plastic must be appliedimmediately following 15treatment and then removed after completion of the EXAMPLE treatment Aformulation as follows:

The present invention provides a new slow release 2 parts f hydroxyethylcellulose fumigant which eliminates the need to provide a cover 4 pans fpropylene glycol over the treated area While p o g equal or better 94parts sodium methyl dithiocarbamate solution fumigant effectiveness.(Same as Example f (llscovered that, 1f y of Standafd $011 was appliedto a field as in Example I with like results. fumigants is incorporatedwith a protective colloid and a stabilizer and preferably with ahumectant, the resultant product will bestabilized, its effectivenessand effir i I P m v ciency will be markedly improved. Preferably weuseas A formulation of 98 parts VPM Soil fumigant (Du the protectvecolloid hydroxyethyl cellulose, sodium Poms Sodium methyldithiocarbamate) and 2 parts algmates Sodmm carboxymethyl cellulosenatural droxyethyl cellulose was injected in soil alongside a gums andwater soluble resins. As humectants we prewarehouse in Fort Myers Fla.Where nut grass had fer glycols such as propy g y ethylene g been aconstant problem at a rate of l pint/100 linear g|ycerme' sorbltols andthe hke known humectants feet. Two weeks later no weeds were growing intreated Preferably we use hydroxyethyl cellulose as the protecarea. tivecolloid and propylene glycol as the humectant. 7

Soil fumigants made according to our invention using 5 I l E LE any ofthe well known conventional fumigants are sta- VPM and Vamoose (thecomposition of Ex 5 mp1 6 I") bllized and improved in efficiency andvalue. Extensive were applied to Selected p1 Ots each of 2 Square yardsfield tests have shown that greater residual effect 15 Fifteen dayslater Hicks tobacco Seed was planted in ach'eved and effectiveness 15 "P9 l one square yard and three 18 inch rows of okra and A broadformulation for use in practicing thls mven- 40 three 18 inch rows ofbeans were planted would be: The seven test plots were as follows: 23 to36 parts of fumigant 60 to 67 parts of water 1 to 4 parts of protectivecolloid :rrigateg PM s1 (gallsaore "I ate amoose a S acre 0 to 6 partsof humectant 3. Irrigated Vamoose I09 Gals/acre A narrower and preferredrange would be: 4. fiomirrigated VPM 2 s1 (gals/acre 5. on" ri atedVanno l Gals a 34 to parts of fumlgant 6. Non-ii rigated Vanno zz 109Gals/ al rt: 58.5 to 60 parts of water 7. Control 1 to 2 parts ofprotective colloid 4 to 5 parts of humectant Eleven days after plantingthe number of nut grass The invention may perhaps be best illustrated byreferplants per square foot were counted with the following ence to thefollowing examples. results: g v

VPM-Sl Gals Vamuose 8] Gals Vamoose I09 Gals CHECK Irrigated 51 74 69179 Non-irrigated 57 52 97 92 Non-irrigated 57 M 89 Non-irrigated 23 7142 i Average 47 63 74 I07 TEST CROP STAND Hicks tobacco, Beans, Okra.Stand counts were made at same time as follows:

IRRIGATED BEAN OKRA T -81 als/A l5,l5,l5 (45) 30,26,27 (83) GerminatingVamoose 8| Gals/A l6,l7,l7 50 26.27.22 75 do. Vamoose I09 Gals/A|5,l6,l7 (48) 2526,25 (76) do.

NON-IRRIGATED P -8! aIs/A 17,17,14 4s) 25,213.26 79 do. Vamoose 81Gals/A l7,l5,l7 (49) 23,26,215 (75) do. Vamoose l09 Gals/A l4,l6,l3 (43)27,25,25 (77) do. Vamoose IOQGals/A l6.l6,l3 (45) 21.2625 (72) do.

Unsprayed Plots EXAMPLE V Damage from stubby root nematodes was commonon most all roots. Some fumigated rows showed late A sweet corn testplot was treated with various comnematode damage on outer roots.

mercial soil fumigants in the recommended manner and with a productaccording to our invention called for purposes of this test VAMOOSE. Thetest data is as follows: Com planted 1st picking BEST ROOT DEVELOPMENTlN TREATMENTS Treatments: South Tier North Tier A. Dasanit 106, 1 lb.act/Am row D 2 lb D 2 B. Dasanit 106, 2 lbs. act/A in row zgz I :5 C.EBB-40, 6 Gals/A 1n row vAMoosE 1s Gals. LANNATE 8 lbs.

LANNATE 8 lbs. vAMoosE l8 Gals. D. Lannate, 4 lbs. act/A ncorporatedLANNATE 4 bi LANNATE 4 bx E. Lannate, 8 lbs. act/A Incorporated Emmi) 6Gals, 133.4 6 (3m F. Check CHECK CHECK o. VAMOOSE 18 Gals/A in rowMethod of Evaluation A representative sample 10 feet of row per plot wasselected from either inner two The better treatments showed more fibrousseconrows. A first picking was made of all ears whose silks dary rootsattached to primary roots. Poorer treatments had turned brown. showedshortage of fibrous secondary roots.

South Tier Plots 1) South Middle Tier (2) WORM WORM Treat Wt. Lbs. No.Ears INFEST. Treat Wt. Lbs. No. Ears INFEST.

D 2.75 6 100% D 4 75 8 100% o 5.75 12 100% F* 7.25 14 100% c 4.25 11100% c 0.00 11 100% F 4.00 8 100% o 9.25 14 100% 13* 3.25 7 100% B 5 5010 v 100% E 1.25 5 100% E 5.75 10 90% A -2 9 100% A 6.25 10 100% ToTAL25.50 58 TOTAL 44.75 77 North Middle Tier (3) North Tier 4 WORM WORMTreat Wt. Lbs. No. Ears INFEST. Treat Wt. Lbs. No. Egrs INFEST. T 8.5014 g 100% B. 7.75 12 100% F. 5.00 9 100% D. 7.75 10 100% 0* 3.50 11 100%o 8.25 11 100% A 4.25 12 92% F 3.50 9 100% B 3.25 7 100% E 5.75 10 90% C6.75 l 1- 100% A* 8.00 18 100% E... 1.2.... 100% c 6.00 11 100% TOTAL37.75 76 TOTAL 47.00 81 'Unspruyed Plots CORN YlELD SUMMARY TOTALAVERAGE Lbs. Corn Per No. Ears per Lbs. Corn per No. Ears per TREATMENT40 Ft. 40 Fr. 10 Plot 10 F t. Plot WORMS 0 31.75 51 7.93 12.75 100 c23.00 44 5.75 11.00 100 A 22.75 49 5.68 12.25 98 F 19.75 40 4.93 10.00100 B 19.75 36 4.93 9.00 100 E 19.25 37 4.81 9.25 90 D 18.75 4.68 8.75100 Results of lst picking show VAMOOSE rated No. l, EBB- at No. 2,Dasanit 106 (1 lbs. Act) at No. 3, Check at No. 4, Dasanit W0 (2 lb.act.) at No. 5, Lannate (8 lbs.) at No. 6, and Lannate (4 lbs.) at

Using 5 doz. ears/crate, and 36 rows, the VAMOOSE treatment hereprojects to 308 crates/acre and Check treatment projects to 242crates/acre, an increase of fl-crates/acre.

Root Growth Evaluation Corn Soil Treatments S f rd Fl id J 5 1969 SecondPicking Results June 5, 1969 Representative corn plants from markedareas in South Plots I) worm plots where corn yield was obtained wereused to make N0. Ears Infestation determinations.

One plant from each treatment in South Tier of plots g; :36 2 and NorthTier (Sutan treatment) was carefully dug, g I i root system washed, andclosely examined. 188$:

Cntinued 1 In theforegoing specification we have set out certain secondPicking Results June 1969 preferred compositions and practices of ourinvention, South Teir Plots 1) however, it will be understood that thisinvention may worm WL UK No Ears Infestation otherw se be practlcedw1th1n the scope of the follow 7 Y 5 "1 P949 51. E .00 0 100% W 9141111Total 4.05 4

1. A slow release soil fumigant consisting essentially riddle Tier (2)of sodium methyl dithiocarbamate about 23 to 36 part- D .00 p 0 0 10 s,about 60 to 67 parts water, about 1 to 4 parts protecg g; 5 tive co o dnd p t 6 parts hyms tg g 106% 2. A slow release soil fumigant as claimedin claim 1 A 1 w 4 100% wherein the protective colloid is a memberselected Total l 2 7 from the group consisting of hydroxyethylcellulose, so-

North Middle Tier (3) dium alginates, sodium carboxymethyl cellulose,natu- G 1.00 2 100% ral gums and water soluble resins. F .00 0 .00 0 3.A slow release soil fumigant as. claimed in claim 1 Q 8 2 5 wherein thehumectant is a member from the group c .31 1 100% consisting ofpropylene glycol, ethylene glycol, glycer- Em v Total 3.00 7 meangsorbfiol' a North Tier (4) 4. A slow release soil fumigant as claimedin claim 1 B .75 1 10 3; wherein the protective colloid is hydroxyethylcellulose 1) .8l 3 10 a G n thqh msstsn 1S p qpyl ns 211 99 g 22 g {88;5. A method of soil fumigation which comprises ap- 0 plying an aqueoussolution of the composition about 23 C. 0 to 36 parts sodium methyldithiocarbamate, about 60 Total S.()0 l l V to 67 parts water, about lto4 parts protecuve colloid CORN YIELD SUMMARY Second Picking TOT 1.AVERAGE Lbs. Corn No. Ears Lbs. Corn No. Ears TREATMENT per F1. per 10Ft. per [0 Ft. Worms per 40 Ft.

F 3.81 8 .95 2 100 B 2.56 6 .64 1.5 100 A 2.31 5 .57 1.2 100 G L69 3 .42.75 100 C 1.158 4 .42 .75 100 D L62 5 .40 1.25 100 E 1.50 4 .37 1 100Results of second picking showed there was only a fraction of yield ascompared to the first picking. No. l was check. No. 2 Dasanit 2 lbs. No.3 Dasanit 1 lb.. No. 4 was Vamoose, No. 5 was EBB-40, No. 6 Lannate 4lbs., and No. 7 Lannate 8 lbs. TOTAL CORN YIELD SUMMARY FIRST AND SECONDPlCKlNG One change occurred when yield of first and second picking weretotaled. Dasanit 100 at 1 lb. moved from 3rd to 2nd place replacingEBB-40 at 6 Gal/A.

TREATMENT LBS. CORN 40 Fl". NO. EARS 40 FT. lst Vamoose l8 Gals. 33.4454 2nd Dasanit l lb. 25.06 54 3rd EBB-40 6 Gals. 24.68 48 4th CHECK23.56 48 5th Dasanit 2 lbs. 22.3] 42 6th Lannate 8 lbs. 20.75 4l 7thLannate 4 lbs. 20.37 40 The foregoing examples show the effectivenss ofthe and up to about 6 parts of humectant to the soil to be soil fumigantof this invention as compared with con- 55 treated without a surfacecover. ventional soil fumigants without the problems and expense ofcovering the treated area. =1=

Patent No. 3,82 7 Dated June 28, 1974 Inventor) Wayne W. Wells,-James R.Christie and Julian Jackson It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 5, "CORNXIELD SUMMARY, Second Picking" heading should read asfollows TOTAL AVERAGE Lbs.Corn No. Ears Lbs, Corn No. Ears TREATMENT per40 Ft. per 40 Ft. per 10 Ft, per 10 Ft. Worms Column 6, Claim 1. shouldread as follows l A slow release soil fumigant consisting essentially ofan aqueous solution of about 23 to 36 parts sodium methyldithiocarbamate, about 60 to 67 parts water about 1 to 4 part protectivecolloid and up to 6 parts humectant.

Signed and sealed this 12th day of November 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR C. MARSHALL DANN Attesting Officer Commissioner ofPatents FORM (0459) USCOMM-DC 60376-P69 Q U.$. GOVERNMENT PRINTINGOFFICE 1959 0-35533

2. A slow release soil fumigant as claimed in claim 1 wherein theprotective colloid is a member selected from the group consisting ofhydroxyethyl cellulose, sodium alginates, sodium carboxymethylcellulose, natural gums and water soluble resins.
 3. A slow release soilfumigant as claimed in claim 1 wherein the humectant is a member fromthe group consisting of propylene glycol, ethylene glycol, glycerine andsorbitol.
 4. A slow release soil fumigant as claimed in claim 1 whereinthe protective colloid is hydroxyethyl cellulose and the humectant ispropylene glycol.
 5. A method of soil fumigation which comprisesapplying an aqueous solution of the composition about 23 to 36 partssodium methyl dithiocarbamate, about 60 to 67 parts water, about 1 to 4parts protective colloid and up to about 6 parts of humectant to thesoil to be treated without a surface cover.